semicrystalline Syllabification: (sem·i·crys·tal·line)Pronunciation: /ˌsemēˈkristələn, ˌsemˌī-, -ˌlīn/Definition of semicrystalline adjective Chemistry (of a solid) possessing crystalline character to some degree. semicrystalline in other Oxford dictionaries Definition of semicrystalline in the British & World English dictionary